Is anyone else seeing this sign-in error when selecting "View account" from Office.com? The page reports: "AADSTS900023: Specified tenant identifier '{{{tenantid}}}' is neither a valid DNS name, nor a valid external domain." It has been happening for users in multiple regions, so I'm wondering whether this is a Microsoft service issue or if there's a local workaround or troubleshooting step worth trying.
2 Answers
There doesn’t seem to be a reliable workaround reported yet. Opening a support case with Microsoft and checking the Microsoft 365 service health dashboard are the main practical steps while waiting for the service to recover.
Several people are seeing the same error, including users in both Europe and the United States. Since it’s affecting multiple organizations and regions at once, it most likely points to a Microsoft-side authentication problem rather than a tenant configuration issue.
That matches what I’m seeing—this has continued for more than an hour, and the issue isn’t limited to one client or location.